Same message ID, 2 different senders


New Email

Someone in my company got an email from a bogus email address ( that spoofs our company's domain. I'm using Exchange, so I check the message tracker for and I get the message ID - 123456@WHITMANTANIA.

I then check the smart host logs for the message ID. I get a hit but the sender address is completely different. Its, and not

I run message tracker again, but search for The result is a mail with the same messageID. Can anybody explain this?